1. Technical Field
The present invention relates to a method and apparatus for removing hazardous waste materials, such as particulate matter and fluids, from localized work spaces. More particularly, the invention relates to an improved glove bag and its method of use in connection with confining and removing such materials from the work space about a pipe section coated with or containing the hazardous material. The preferred embodiment of the present invention is described in connection with protecting a worker from exposure to asbestos particles during removal of asbestos coatings or insulation from a pipe; however, it is to be understood that the invention has broader utility and may serve to prevent the worker from exposure to any other type of hazardous particles or fluids.
2. Discussion of the Prior Art
It is long been known to utilize glove bags to protect workers from exposure to hazardous materials. Examples of such glove bags thusly utilized may be found in U.S. Pat. Nos.: 4,626,291 (Natale); 4,812,700 (Natale); 4,783,129 (Jacobson); 4,820,000 (Jacobson); 4,842,347 (Jacobson); 4,746,175 (Hamlet et al). Other glove bags and related apparatus are disclosed in Canadian Patent No. 1,188,191 (Atkinson); British Patent No. 1,567,270 (Atkinson); U.S. Pat. No. 4,809,391 (Soldatovic); and U.S. Pat. No. 4,604,111 (Natale). These prior art glove bags are typically made of transparent polyethylene, polyvinylchloride, or other similar collapsible sheet material having one end that can be wrapped about a section of pipe and sealed against the pipe to prevent leakage. The other end of the bag takes the form of a seam toward which the front and back sides of the bag converge to direct and collect waste material falling from the pipe section. Glove-like sleeves extend into the bag to permit the worker to perform the necessary work functions on the enclosed pipe section. Before stripping asbestos from the pipe section, a waste hose or nozzle is typically inserted through a sealable port to permit the pipe section to be wetted. As the asbestos coating is stripped, the heavier wetted asbestos particles tend to fall and be collected at the bottom seam of the bag, thereby reducing the amount of airborne asbestos particles in the work space. After the stripping operation is completed, a tube attached to a vacuum source is inserted through the same or a different sealable port to remove any remaining airborne asbestos particles while partially collapsing the bag. The bag is sealed by twisting and tying or taping it closed with the enclosed debris in the bottom portion of the bag, which is then removed from the pipe section and disposed of pursuant to prescribed safety procedures.
Prior art glove bags have proven to be less safe for the worker than desirable. More particularly, if the seal about the pipe is not complete, it is possible to contaminate the surrounding environment with asbestos particles during the stripping operation. Moreover, even if there is a proper seal about the pipe section, when suction is applied to the bag after the stripping operation, the bag tends to prematurely collapse before all of the particles inside the bag can be drawn into the suction tube. Consequently, upon removal of the bag from the pipe section, a considerable quantity of asbestos particles escapes into the environment.
It has been proposed (see the Natale U.S. Pat. Nos. 4,626,291 and 4,812,700) that a low level of suction be maintained in the bag during the stripping operation by means of a suction tube inserted through the self-sealing access port. However, this has not proven to be practical. Specifically, if the bag is properly sealed about the pipe section, applied suction forces cause the bag to collapse and prevent wetted particles of asbestos from falling to the bottom for safe collection. The only way to prevent the Natale bag from collapsing is to provide an incomplete seal about the pipe section, or elsewhere in the bag. This, however, sacrifices safety since the asbestos particles are able to escape through the incomplete seal or other opening.
Another prior art waste containment system is disclosed in U.S. Pat. No. 4,505,190 (Fink et al). This patent discloses an exhaust hood made from collapsible transparent material supported by a rigid framework of rods along the edges of the hood walls. The hood is secured about a pipe section and includes a lid that may be opened to provide manual access to the hood interior. A suction tube communicates with the hood interior to continuously draw air therefrom. Replacement air is provided via the open manual access lid. This hood approach is not safe for asbestos removal operations since the worker's gloves, which are not part of the hood, and other clothing become contaminated.